Holding device for loom let-off mechanism



Dec. 8, 1942. R. G. TURNER HOLDING DEVICE FOR LOM LET-OFF VMECHANISM Filed Feb. 2, 1942 VINVENTQR ATTRNEY Patented Dec. 8, 1942 HOLDING DEVICE FOR LOOM LET-OFF MECHAN ISM Richard G. Turner, Worcester, Mass., assignor to Crompton & Knowles Loom Works, Worcester, Mass., a corporation of Massachusetts Application February 2, 1942, Serial No. 429,196

8 Claims.

This invention relates to improvements in let-oi mechanisms for looms and it is the general object of the invention to provide means for holding the let-oil' mechanism and associated warp beam in a fixed position during periods of inactivity of the loom.

Certain types of let-oils employ a weight so connected to the warp beam as to exert a constant rearward pull on the warp threads to tension them. When the loom is stopped the weight has the effect of causing retrograde movement of the beam and draws the fell of the cloth rearwardly the result of which is to produce a thick place when weaving is resumed. It is an important object of my present invention to provide means for holding some part which moves with the warp beam in stationary position when the loom is at rest to prevent retrograde movement of the fell of the cloth.

In the weaving of fine fabrics having a high number of picks per inch it is important that the warp beam be maintained in the angular position which it occupies at the moment the loom is stopped and it is a further object of my further invention to provide means operative immediately upon stoppage of the loom to engage the beam head or other part moving therewith to hold the warp beam against angular movement under action of the Weight.

It is a further object of my present invention to provide electro-magnetic means de-energized during loom operation but energized upon loom stoppage to move into holding relation with respect to the warp beam head to hold the latter against turning and in whatever position it may occupy at the time of loom stoppage.

With these and other objects in View which will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth.

In the accompanying drawing, wherein a convenient embodiment of my invention is set forth,

Fig. 1 is a side elevation of a loom having my invention applied thereto,

Fig. 2 is a rear elevation looking in the direction of arrow 2, showing one end of a warp beam with the let-off mechanism and my invention applied thereto,

Fig. 3 is a side elevation of the holding unit looking in the direction of arrows 3-3, Fig. 2, on an enlarged scale,

Fig. 4 is a horizontal section on line 4-4 of Fig. 3,

Fig. 5 is a side elevation of the holding unit looking in the direction of arrow 5, Fig. 4,

Fig. 6 is an enlarged detailed horizontal section on line 6 8 of Fig. 2, and

Fig. '7 is a diagrammatic view showing the circuit which controls the electro-magnetic holding unit forming an important part of my present invention.

Referring to the drawing, IA have shown a loomv frame Il] with a lay vll having a reed I2Y and driven by the top crank shaft I3 ofthe loom. A shipper rod I5 is journaled in the loom frame and has secured thereto a shipper Vhandle I6 which is in the forward full line position of Fig. l, when the loom is operating but is in therearward dotted line position of that figure when the loom is stopped.

Extending rearwardly from the loom frame is a support I3 for the warp beam I9. The support carries an upright provided with a bearing 2! for the gudgeon 22 of the warp beam. The latter has a barrel 23 to which is secured a beam head 24 made of a magnetizable material such as cast iron or steel. The warp threads W extend forwardly from the beam through harness frames 25 and the reed I2 to the weaving point or fell F of the cloth. The cloth C extendsk forwardly from the fell in well-known manner to be wound on a cloth roll not shown.

The type of let-off set forth herein and to which my invention more particularly applies is weighted in such a way as to exert a constant rearward force on the warp beam tending to turn it in a counter-clockwise direction as viewed in Fig. 1. The particular let-off mechanism shown in Figs. 1 and 2 includes a worm gear 3U secured to the beam head I9 and meshing with` a worm 3l mounted for rotation on a carrier 32 movable about the axis of the warp beam. The worm is secured to a shaft 33 to the upper end of which is secured a gear 34 actuated by a small rack 35 slidable in the carrier 32 against spring action. A segment 36 is secured to the carrier 324 andby means of a cable or rope 31 supports the weight 38.

A wing 39 is pivoted as at 40 to the upright` 2!! and has an arm 4| attached to a rod 42 which extends forwardly to be connected to some regularly moving part of the loom such as the lay. A dash pot held in xed position receives a piston 46 on the lower end of a rod 41 the upper end of which is attached as at 48 to the segment 36.

During normal loom operation as the warp threads move to the right as viewed in Fig. 1 the warp beam turns in a clockwise direction to` cause the segment 36 to lift the weight 36. The wing 39 has regularly recurring motions toward the beam head I9 and when the latter has moved suiciently to bring the rack 35 Within the range of movement of the wing the latter pushes the rack to cause a slight angular motion of shaft 43 with consequent angular motion of the worm 3| in such a direction as to turn the carrier 32 rearwardly, or in a counter-clockwise direction as viewed in Fig. 1, with respect to the beam head I 9 and the worm gear 30. In this way the weight rises and falls during continued weaving and always exerts a rearward pull on the warp threads. When the loom is stopped the weight continues to exert a rearward pull on the warp.

The matter thus far described of itself forms no part of my present invention and the let-off may be the same as that set forth in prior patent to Payne No. 1,803,143 to which reference may be had for a further` description of the structure and operation of the let-off mechanism. It is thought suicient for present purposes to state that the beam head I9 is subject to a constantly exerted force tending to turn it in a rearward direction the effect of which is to cause retrograde movement of the fell F of the cloth during periods of inactivity of the loom. I do not wish to be limited, however, to the type of weight actuated let-off mechanism shown in Figs. 1 and 2.

In carrying my present invention into effect I provide electro-magnetic means for holding the warp beam stationary during periods of loom inactivity and as shown herein I effect this result by means of an electro-magnet M mounted on a fixed support and placed for engagement with the magnetizable beam head I9. Referring particularly to Figs. 2 and 6, I provide a support 50 held on the floor which supports the loom by bolts I and provide the support with a pin 52 on which is pivoted an upwardly extending lever 53. An arm 54 xed with respect to the support has a spring 55 whichas shown in Fig. 6 extends around a part of lever 53 and tends normally to move the latter away from the beam head I9 to the full line position shown in Fig. 2 against an adjustable stop 56 on arm 54.

The upper end of the lever 53 has bolted thereto as at 58 the body 59 of the electro-magnetic unit M. This body has a shell 60 and a core 6I located therein and around which is located an electric coil 62 to create a magnetic field in the shell and core. The coil is connected by wires 65 and 66 to an external circuit set forth in Fig. '7.

The shipper handle is provided with a Contact 10 to engage the electrodes 'II and 12 xed to but insulated from the loom frame as suggested in Fig. 1. Wire 66 is connected to electrode 1I, while electrode 'I2 is connected by wire 13 to one side of a source of electric power P the other side of which is connected to wire 65.

Under normal running conditions the contact 10 is moved rearwardly and the electrodes 1I and 'I2 are disconnected. The circuit shown in Fig. '7 is therefore open as suggested by the dotted position of the shipper handle I6 and the electro-magnet is de-energized and preferably held spaced a slight distance from the beam head I9 by spring 53 and stop 56. Under these conditions the let-oir mechanism operates in usual manner as already described. Whenever the loom is stopped for any reason, as by a weft or warp stop mechanism not shown, the shipper handle will move from the full to the dotted line position of Fig. 1 and cause the contact 'I0 to connect the electrodes 'II and 12 electrically, whereupon current will ow in the circuit shown in Fig. 7 through the coil 62 to energize the latter and cause the unit M t0 be attracted to the beam I9, as indicated in dotted lines in Fig. 2. When in this position the electro-magnet, the lever 53 and the support 50 are held in close holding relation with respect to the beam head at a point spaced from the axis of the warp beam to prevent rotation of the latter. The circuit is maintained closed as long as the loom is stopped and the magnet is of suicient strength to resist the tendency of weight 38 to move the fell of the cloth F rearwardly. Upon resumption of weaving the contact 'IIJ moves rearwardly to break the circuit, whereupon spring 55 moves the magnet away from the beam head I9 and the warp beam is free to unwind warp without interference on the part of the magnet.

From the foregoing it will be seen that I have provided simple mechanism for preventing rotation of the warp beam during periods of inactivity of the loom. It will be seen that this .means includes an electro-magnet which can engage the beam head I9 at any of its angular positions and serves to arrest rotary motion of the beam under action of the weight 38. The magnet is mounted on a lever or the like which is carried by a fixed support. Inasmuch as the magnet can be attracted to the beam head I9 whenever the circuit is closed and in any regular position of the beam, it serves to prevent even the slightest degree of rearward movement of the fell of the cloth. l

Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and I do not wish to be limited to the details herein disclosed, but what I claim is:

l. In a let-off mechanism for a loom having a warp beam which ,tends to turn rearwardly during periods of loom inactivity, a magnetizable member' secured to the warp beam, an electromagnetic holding device normally deenergized during loom operation and located adjacent to said magnetizable member, and electric means operative upon stoppage of the loom to energize said holding device and cause the latter to establish electro-magnetic holding relation with respect to said member to prevent angular motion of the warp beam.

2. In a loom let-off mechanism for a warp beam having a magnetizable beam head secured thereto, an electro-magnetic device adjacent to the beam head and normally deenergized during loom activity, and electric means to energize the device when the loom stops to cause said device to establish electro-magnetic holding relation with the head to prevent angular movement of the warp beam..

3. In a loom let-off mechanism for a Warp beam having a magnetizable beam head secured thereto, loom shipping mechanism movable from running to stopping position when the loom is stopped, an electro-magnetic device adjacent to the beam head and normally deenergized during loom operation, and electric means controlled by the shipping mechanism and caused by the latter when the same moves to stopping position to energize the device and cause the latter to move into electro-magnetic holding relation with respect to the head to prevent angular movement of the Warp beam. K

4. In a loom let-01T mechanism for a Warp beam having a magnetizable member secured thereto, a xed support, an electro-magnetic device movably mounted on said support and normally deenergized during loom activity, and electric means operative upon stoppage of the loom to energize the device and cause the same to move into electro-magnetic holding relation with the head to prevent angular movement of the Warp beam.

5. In a loom let-off mechanism for a Warp beam having a magnetizable member secured thereto, a stationary support, electro-magnetic means normally deenergized during 100m operation and movably mounted on the support, a stop on said support to hold the electro-magnetic means adjacent to the head, and electric means operative upon stoppage of the loom to energize said electro-magnetic means to cause the same to move into electro-magnetic holding relation with respect to the head to prevent angular movement of the warp beam.

6. In a 100m let-01T mechanism for a warp beam having a magnetizable beam head secured thereto, a fixed support, electro-magnetic means movably mounted on the support and normally cie-energized during loom activity, a stop on said support, resilient means to hold thel electromagnetic means against said stop and adjacent to the head during loom operation, and electric means to energize the electro-magnetic means upon stoppage of the loom to cause said electromagnetic means to move away from said stop and into electro-magnetic holding relation with respect to the head to prevent angular movement of the warp beam.

'7. In a loom having a Warp beam provided with a beam head which turns angularly during loom operation and is made of magnetizable material, an electro-magnetic device adjacent to said head and normally de-energized during loom operation, and electric means operative upon stoppage of the loom to energize said device and cause the same to establish electro-magnetic holding relation with respect to the head to prevent the latter from moving from the angular position which it occupied at the time of loom stoppage. l

8. In a loom having a Warp beam and a magnetizable member rotatable therewith and held against relative angular movement with respect to the beam, an electro-magnetic member normally 1e-energized during loom activity, means to mount one of said members for movement toward the other member, and electric means operative upon stoppage of the loom to energize the electro-magnetic member to cause relative movement of said members into electro-magnetic holding relation with respect to each other to prevent angular movement of the Warp beam.

RICHARD G. TURNER. 

